Coating for rubber gloves

ABSTRACT

A composition for a damp hand donnable glove using a novel coating. The novel coating results in the formulation of domains of variable size and height. The coating has a polyurethane polymer, and aqueous dispersion and a surfactant.

CROSS-REFERENCE TO RELATED APPLICATION

This application is a continuation of U.S. patent application Ser. No.10/343,551, filed Jul. 1, 2003, which is a §371 application ofPCT/US01/23954, filed Jul. 31, 2001, which claims the benefit of U.S.Provisional Application Ser. No. 60/222,351, filed Aug. 1, 2000, all ofwhich are incorporated herein by reference in their entirety.

FIELD OF THE INVENTION

This invention relates to a damp hand donnable glove produced using anovel coating formulation that yields domains variable in size andheight on the surface of the glove.

BACKGROUND OF THE INVENTION

Medical, surgical and other gloves, made of a rubber latex, aretypically manufactured so that these rubber articles tightly conform tothe human hand. Because of this tight fit, such gloves are typicallylubricated on the skin-contacting inner surface in order to facilitatedonning of the articles. The standard lubricant utilized for thispurpose is dusting powder, e.g., cross-linked corn starch. However, itis also desirable to have a glove that does not rely on an internalsurface lubricant for donnability. Therefore, attempts have been made toeliminate the internal surface lubricants while at the same timeproviding an inner glove surface that will aid in the donning of theglove.

Various methods have been proposed to provide slip finishes on rubberarticles of this type. For example, the surface of a rubber glove can behalogenated with bromine or chlorine to make it slippery. Thistreatment, however, has certain disadvantages well-known in the art andtypically does not produce a glove that is easier to don that a gloveinternally coated with dusting powder. One prior art glove provides aslip finish comprising a rubber latex blended with a resin latex. Thisapproach, while lowering the coefficient of friction of the rubberglove, does not significantly improve donnability. Yet another prior artglove is made with granular material deposited on the inner,skin-contacting surface of a single-layer vinyl or silicone glove inorder to reduce the frictional contact between the glove layer and theskin of the wearer and, thus, to aid in the donning of the glove. Use ofthis glove, however, results in the granular material being abraded fromthe inner glove surface thus generating loose particulate matter. It istherefore desirable to have a glove with improved donnability that doesnot generate loose particulate matter. It is further desirable to have adamp-hand donnable glove having domain formations on the glove surfacethat are produced during the manufacturing process.

SUMMARY

In one embodiment, the present invention provides a damp-hand donnableglove produced using a novel coating formulation that yields domainsvariable in size and height on the surface of the glove. In anotherembodiment, the present invention also provides a formulation useful inproducing gloves in a conventional dipping process where the gloves somade exhibit domain formation. In still another embodiment, the presentinvention further provides a process for the manufacture of a polymericcoating useful in the generation of domain formation on gloves madeusing the polymeric coating.

DESCRIPTION OF THE DRAWINGS

FIG. 1 is a scanning electron photomicrograph of a glove surface madeaccording to the principles of a first embodiment of the presentinvention.

FIG. 2 is a scanning electron photomicrograph of a glove surface of theprior art.

FIG. 3 is a scanning electron photomicrograph of a glove surface madeaccording to a second embodiment of the present invention.

FIG. 4 is a scanning electron photomicrograph of a glove surface madeaccording to the second embodiment of the present invention at a 0%stretch.

FIG. 5 is a scanning electron photomicrograph of a glove surface madeaccording to the second embodiment of the present invention at a 500%stretch.

FIG. 6 is a scanning electron photomicrograph of a glove surface madeaccording to the second embodiment of the present invention at 5×700%.

FIG. 7 is a scanning electron photomicrograph of a glove surface madeaccording to the second embodiment of the present invention after abreak.

FIG. 8 is a scanning electron photomicrograph of a glove surface madeaccording to a third embodiment of the present invention at a 0%stretch.

FIG. 9 is a scanning electron photomicrograph of a glove surface madeaccording to the third embodiment of the present invention at 5×700%.

FIG. 10 is a scanning electron photomicrograph of a glove surface madeaccording to the third embodiment of the present invention after break.

FIG. 11 is a scanning electron photomicrograph of a glove surface madeaccording to the fourth embodiment of the present invention at a 0%stretch.

FIG. 12 is a scanning electron photomicrograph of a glove surface madeaccording to the fourth embodiment of the present invention at a 500%stretch.

FIG. 13 is a scanning electron photomicrograph of a glove surface madeaccording to the fourth embodiment of the present invention at 5×700%.

FIG. 14 is a scanning electron photomicrograph of a glove surface madeaccording to the fourth embodiment of the present invention after break.

FIG. 15 is a scanning electron photomicrograph of a glove surface madeaccording to the fifth embodiment of the present invention at a 0%stretch.

FIG. 16 is a scanning electron photomicrograph of a glove surface madeaccording to the fifth embodiment of the present invention at a 500%stretch.

FIG. 17 is a scanning electron photomicrograph of a glove surface madeaccording to the fifth embodiment of the present invention at 5×700%.

FIG. 18 is a scanning electron photomicrograph of a glove surface madeaccording to the fifth embodiment of the present invention after break.

FIG. 19 is a scanning electron photomicrograph of a glove surface madeaccording to the sixth embodiment of the present invention at a 0%stretch.

FIG. 20 is a scanning electron photomicrograph of a glove surface madeaccording to the sixth embodiment of the present invention at a 500%stretch.

FIG. 21 is a scanning electron photomicrograph of a glove surface madeaccording to the sixth embodiment of the present invention at 5×700%.

FIG. 22 is a scanning electron photomicrograph of a glove surface madeaccording to the sixth embodiment of the present invention after break.

FIG. 23 is a scanning electron photomicrograph of a glove surface madeaccording to the seventh embodiment of the present invention at a 0%stretch.

FIG. 24 is a scanning electron photomicrograph of a glove surface madeaccording to the seventh embodiment of the present invention at a 500%stretch.

FIG. 25 is a scanning electron photomicrograph of a glove surface madeaccording to the seventh embodiment of the present invention at 5×700%.

FIG. 26 is a scanning electron photomicrograph of a glove surface madeaccording to the seventh embodiment of the present invention afterbreak.

DETAILED DESCRIPTION

There is provided according to the principles of the present invention,an aqueous-based polymeric coating including, in one embodiment of thepresent invention, water, a polyurethane dispersion, a sodiumpolymethacrylate solution and a polyvinyl chloride latex is prepared byfirst mixing the water, the polyurethane dispersion, and the polyvinylchloride latex, to form a first mixture. Then, the sodiumpolymethacrylate is metered into the first mixture to form the coatingof the present invention. Metered addition of the sodiumpolymethacrylate, under mixing, facilitates agglomeration of thepolyvinyl chloride. Agglomeration of the polyvinyl chloride enhances theformation of domains on a glove surface.

According to the principles of the present invention, it has beendemonstrated that the formation of domains on the interior of the glovesurface greatly enhances donnability. The domains reduce the coefficientof friction between the interior glove surface and the skin, thusenhancing wet-hand donnability.

As but one example of a coating made according to the principles of thepresent invention, Table 1 below presents a formulation useful ascoating for the formation of domains on a glove surface. TABLE 1 ItemIngredient % Solids (w/w) % used 1 Water — Balance 2 Solucote 35 3.0 3VYCAR 576 58 2.5 4 GOOD-RITE 30 0.5 K-765

VYCAR 576 is plasticized polyvinyl chloride latex, available from B FGoodrich Specialty Chemicals, Cleveland, Ohio. VYCAR 576 is an emulsionincluding water, polyvinyl chloride solids, di(2-ethylhexyl) phthalate,and an anionic synthetic emulsifier. GOOD-RITE K-765 is a sodiumpolymethacrylate solution available from B F Goodrich SpecialtyChemicals, Cleveland, Ohio. GOOD-RITE K-765 is an aqueous solution of asodium polymethacrylate having a molecular weight, by conventional gelpermeation chromatographic methods, of about 30,000. Solucote is aconventional polyurethane dispersion available from Soluol ChemicalCompany, Warwick, R.I.

The percentages provided in Table 1 are illustrative of but oneembodiment of the present invention. The solids contents of theplasticized polyvinyl chloride latex, the sodium polymethacrylatesolution, and the polyurethane dispersion may be varied over the rangesof concentrations found in commercially available products. Theconcentration of these components in the coating of the presentinvention may accordingly be varied. However, according to theprinciples of the present invention, a polyurethane dispersion at fromabout 0.1% (w/w) to about 10% (w/w), a plasticized polyvinyl chloride atfrom about 0.1% (w/w) to about 10% (w/w), and a sodium polymethacrylatesolution at from about 0.1% (w/w) to about 10% (w/w), each based on thetotal coating weight, may be used in making the coating of the presentinvention.

A process for making a glove, using a coating of the present invention,is described as follows. A standard latex coagulant, well known by thoseof ordinary skill in the art, is applied to a clean ceramic former anddried. A standard latex coagulant generally comprises an aqueoussolution of a divalent cationic metal salt, a surfactant or wettingagent, and a release powder. The typical divalent metal salt includes,but is not limited to calcium nitrate and the typical class ofsurfactant or wetting agent is nonionic while the typical release powderis calcium carbonate. Of course, alcohols may be used in lieu of water,other divalent and trivalent cationic metal salts can be used, othersurfactant types may be used that are salt stable and other releasepowders include, but are not limited to starch and talc.

The former is dipped into compounded latex to form a rubber film in theshape of a hand. The gelled latex is leached in water. The leached filmenters the coating solution of the present invention. A dry time isincorporated following the coating solution to promote domain formation.The glove is cured and then optionally silicone coated to enhance damphand donnability.

FIG. 1 illustrates a scanning electron photomicrograph of a glovesurface made in one embodiment of the present invention. Ridges R can beclearly seen in FIG. 1. These ridges R define the domains on the glovesurface. FIG. 2, on the other hand, illustrates a scanning electronphotomicrograph of a glove surface of the prior art. A comparison ofFIGS. 1 and 2 demonstrates the lack of domain formation on the surfaceof the glove of the prior art as compared to the glove surface of thepresent invention.

In a second embodiment of the present invention, there is provided anaqueous based polymeric coating that includes water, a styrene acrylicemulsion, a nonionic surfactant, an ionic surfactant, an aqueous waxdispersion and an amount of 10% solution of potassium hydroxide. In thisparticular embodiment of the present invention, the styrene acrylicemulsion is used as a substitute for the polyurethane used in the firstembodiment of the donning coating formulation.

The second embodiment of a donning coating made according to theprinciples of the present invention, presenting a formulation useful ascoating for the formation of domains on a glove surface is set forth inthe table below: TABLE 2 Item Ingredient % Solids % Used 1 Water —Balance 2 Rhoplex TR-3388 44 3.0 3 Aquamat 213 30 2.0 4 Igepal CO-897 700.05 5 Darvan WAQ 66 0.03 6 KOH 10 0.12

Rhoplex TR-3388, a polymer selected to substitute the polyurethane latexin the donning coating, is a styrene acrylic emulsion, available fromRohm & Haas. Aquamat 213 is an aqueous wax dispersion. Igepal CO-897 isa nonionic surfactant and Darvan WAQ is an anionic surfactant used as anemulsion stabilizer.

The percentages set forth in Table 2 are merely illustrative of but oneembodiment of the present invention. The solids content of the emulsion,the aqueous wax dispersion, both the nonionic and anionic surfactants aswell as the potassium hydroxide may be varied over the ranges ofconcentrations found in commercially available products. Waxes may besynthetic or natural. The natural waxes that may be generally usedinclude montan, carnauba, bees wax, bayberry-myrtle, candelialla,caranday, castor bean, asparto-grass, Japan, ouricury, retamo-ceri,mimbi, schlack, spermaceti, sugar-cane and wool lanolin. Synthetic waxesgenerally include polyethylene and modified polyethylenes, polypropyleneand modified polypropylenes, and hydrogen-based materials.

The concentrations of these components in the coating of the secondembodiment of the present invention may accordingly be varied. However,according to the principles of the second embodiment of the presentinvention, an emulsion from about 0.1% (w/w) to about 10% (w/w), anaqueous wax dispersion of from about 0.1% (w/w) to about 10% (w/w), anonionic surfactant from about 0.01% (w/w) to about 0.1% (w/w), ananionic surfactant from about 0.01% to about 0.1% (w/w) and an amount ofpotassium hydroxide from about 0.01% to about 1.0% (w/w), each based onthe total coating weight, may be used in making the coating of thepresent invention.

FIG. 3 illustrates a scanning electron photomicrograph of a glovesurface made in the second embodiment of the present invention. LikeFIG. 1, ridges R can clearly be seen, the ridges R defining the domainson the glove surface. FIGS. 4-7 illustrates a scanning electronphotomicrograph of the glove surface from a 0% stretch through a seriesof stretches continuing to the breaking point as illustrated in FIG. 7.As is shown, the domains on the glove surface remain even as the gloveis stretched to the breaking point.

In a third embodiment of the present invention, there is provided anaqueous based polymeric coating that includes water, a styrene acrylicemulsion and a surfactant. In this particular embodiment of the presentinvention, the styrene acrylic emulsion, or any other emulsion known bythose skilled in the art, may be used as a substitute for thepolyurethane used in the first embodiment in the donning coatingformulation.

The third embodiment of a donning coating made according to theprinciples of the present invention, presenting a formulation useful ascoating for the formation of domains on a glove surface is set forth inthe table below: TABLE 3 Item Ingredient % Solids (w/w) % Used 1 Water —Balance 2 Rhoplex TR-3388 44 2.826 3 Triton X-114 100 0.02

Rhoplex TR-3388, a polymer selected as a substitute for a polyurethanelatex in this embodiment of the present invention of the donningcoating, is a styrene acrylic emulsion, available from Rohm & Haas.Triton X-114 is a surfactant that is added to act as a stabilizer forthe Rhoplex TR-3318. The surfactant assists in the formation of domainson the glove surface and in improving adhesion.

The percentages set forth in Table 3 are merely illustrative of but oneembodiment of the present invention. The solids content of the emulsionand the surfactant may be varied over the ranges of concentrations foundin commercially available products. The concentration of thesecomponents in the coating of the third embodiment of the presentinvention may accordingly be varied. However, according to theprinciples of the third embodiment of the present invention, an emulsionfrom about 0.1% (w/w) to about 10% (w/w) and a surfactant from about0.01% (w/w) to about 0.1% (w/w), each based on the total coating weight,may be used in making the coating of the present invention.

FIG. 8 illustrates a scanning electron photomicrograph of a glovesurface made according to the third embodiment of the present invention.Ridges R can be seen, the ridges R defining the domains on the glovesurface. FIGS. 8-10 illustrate scanning electron photomicrographs of theglove surface from a 0% stretch through a series of stretches continuingto the breaking point as illustrated in FIG. 10. As is shown, thedomains on the glove surface remain even as the glove is stretched tothe breaking point.

Another process for making a glove, using a coating of the presentinvention is set forth below. A standard coagulant, well known by thoseof ordinary skill in the art, is applied to a clean ceramic former anddried. The former is dipped into compounded latex to form a rubber filmin the shape of a hand. The gelled latex is then leached in water. Thelatex film is then normally primed with aluminum sulfate before beingdipped into the donning coating. For the experiments set forth below,the latex film is not primed by the aluminum sulfate, but instead isdipped into the donning coating without being primed. A dry time is thenprovided following the application of the donning coating to promotedomain formation. The glove is then cured and silicone coated to enhancedamp hand donnability.

FIGS. 11-14 illustrate the domain formations of a coating having water,Solucote 1088, Aquamat 213, Igepal CO-897, Darvan WAQ and an amount ofpotassium hydroxide on the latex film that has not been primed withaluminum sulfate. FIGS. 11-14 also illustrate some amount ofdelamination as the film is stretched to its breaking point.

Accordingly, there is provided, in a fourth embodiment of the presentinvention, water, a polyurethane dispersion, an aqueous wax dispersion,a nonionic surfactant, an anionic surfactant and potassium hydroxide. Inthis particular embodiment of the present invention, the amount ofpolyurethane dispersion is increased while the wax dispersion remainsapproximately constant.

The fourth embodiment of a donning coating made according to theprinciples of the present invention, presenting a formulation useful ascoating for the formation of domains on a glove surface is set forth inthe table below: TABLE 4 ITEM INGREDIENT % SOLIDS (w/w) % USED 1 Water —Balance 2 Solucote 1088 35 4.0 3 Aquamat 213 30 2.0 4 Igepal CO-897 700.05 5 Darvan WAQ 66 0.03 6 KOH (10%) 10 0.12

Solucote 1088 is a conventional polyurethane dispersion available fromSolvol Chemical Company, Warwick, R.I. Aquamat 213 is an aqueous waxdispersion that is susceptible to saponification. Igepal CO-897 is anonionic surfactant and Darvan WAQ is an anionic surfactant used as astabilizer.

The percentages set forth in Table 4 are merely illustrative of but oneembodiment of the present invention. The solids content of thepolyurethane dispersion, the aqueous wax dispersion and both thenonionic and anionic surfactants, and the potassium hydroxide, may bevaried over the ranges of concentrations found in commercially availableproducts. The concentrations of these components in the coating of thefourth embodiment of the present invention may be varied. However,according to the principles of the fourth embodiment of the presentinvention, a polyurethane dispersion from about 0.1% (w/w) to about 10%(w/w), an aqueous wax dispersion of from about 0.1% (w/w) to about 10%(w/w), a nonionic surfactant from about 0.01% (w/w) to about 0.1% (w/w),an anionic surfactant from about 0.01% to about 0.1% (w/w) and an amountof potassium hydroxide from about 0.01% to about 1.0% (w/w), each basedon the total coating weight, may be used in making the coating of thepresent invention. It should be evident to those of ordinary skill inthe art that while specific examples of the components of the coating ofthe present invention have been provided, equivalents of thesecomponents are within the scope of this disclosure.

FIG. 15 illustrates a scanning electron photomicrograph of a glovesurface made in the fourth embodiment of the present invention. Asillustrated previously, ridges R define the domains on the glovesurface. FIGS. 15-18 illustrate scanning electron photomicrographs of aglove surface as taken from a 0% stretch and continuously stretchedthrough to the breaking point as shown in FIG. 18. As is illustrated,the domain formations on the glove surface remain even as the glove isstretched to the breaking point.

Accordingly, there is provided, in a fifth embodiment of the presentinvention, water, a polyurethane dispersion, an aqueous wax dispersion,a nonionic surfactant, an anionic surfactant and potassium hydroxide. Inthis particular embodiment of the present invention, the amount ofpolyurethane dispersion is relatively constant while the wax dispersionwas decreased to test the effect on both domain formation and adhesionproperties.

The fifth embodiment of a donning coating made according to theprinciples of the present invention, presenting a formulation useful ascoating for the formation of domains on a glove surface is set forth inthe table below: TABLE 5 ITEM INGREDIENT % SOLIDS % USED 1 Water —Balance 2 Solucote 1088 35 3.0 3 Aquamat 213 30 1.4 4 Igepal CO-897 700.05 5 Darvan WAQ 66 0.03 6 KOH (10%) 10 0.12

Solucote 1088 is a conventional polyurethane dispersion available fromSolvol Chemical Company, Warwick, R.I. Aquamat 213 is an aqueous waxdispersion that is saponified by the potassium hydroxide. Igepal CO-897is a nonionic surfactant and Darvan WAQ is an anionic surfactant used asa stabilizer.

The results of the fifth embodiment of the present invention areillustrated in FIGS. 19-22. As illustrated, domain formation can befound at ridges, R. FIGS. 19-22 show the amount of domain formations ata 0% stretch through to the breaking point. The domains remain on theglove surface even as the glove is stretched to the breaking point.

A preferred embodiment of the present invention is illustrated by thesixth embodiment. There is provided, in the sixth embodiment, water, apolyurethane dispersion, an aqueous wax dispersion, a nonionicsurfactant, an anionic surfactant and potassium hydroxide. In thisparticular embodiment of the present invention, the amount ofpolyurethane dispersion is increased significantly while the waxdispersion level was decreased and showed superior properties on bothdomain formation and adhesion properties.

The sixth embodiment of the donning coating made according to theprinciples of the present invention, presenting a formulation useful ascoating for the formation of domains on a glove surface is set forth inthe table below: TABLE 6 Item Ingredient % Solids (w/w) % Used 1 Water —Balance 2 Solucote 1088 35 8.5 3 Aquamat 213 30 2.0 4 Igepal CO-897 700.05 5 Darvan WAQ 66 0.03 6 KOH 10 0.12

Solucote 1088 is a conventional polyurethane dispersion available fromSolvol Chemical Company, Warwick, R.I. Aquamat 213 is an aqueous waxdispersion that is saponified by the potassium hydroxide. Igepal CO-897is a nonionic surfactant and Darvan WAQ is an anionic surfactant used asa stabilizer.

The results of the sixth embodiment of the present invention areillustrated in FIGS. 23-26. As illustrated, domain formation can befound at ridges, R. FIGS. 23-26 show the amount of domain formations ata 0% stretch through to the breaking point. The domains remain on theglove surface even as the glove is stretched to the breaking point. Asis illustrated, superior domain formations and adhesion properties arefound.

It should be evident to those of ordinary skill in the art that whilespecific examples of the components of the coating of the presentinvention have been provided, equivalents of these components are withinthe scope of this disclosure. The composition may include, for example,an acrylic polymer, a polyurethane polymer, and a polyvinyl chloridepolymer.

1-15. (canceled)
 16. A glove, comprising: a cured protective latex film;and a cured skin contacting polymeric coating adherent to the curedlatex film, the cured skin contacting polymeric coating comprising anacrylic polymer and a plurality of agglomerates dispersed therein,wherein the agglomerates form a plurality of raised domains.
 17. Theglove of claim 16, wherein the glove has improved damp hand donnability.18. The glove of claim 16, wherein the cured protective latex filmcomprises rubber.
 19. The glove of claim 16, wherein the acrylic polymercomprises polymethacrylate.
 20. The glove of claim 16, wherein the curedskin contacting polymeric coating further comprises polyurethane. 21.The glove of claim 19, wherein the cured skin contacting polymericcoating further comprises polyurethane.
 22. The glove of claim 16,wherein the acrylic polymer comprises styrene.
 23. The glove of claim16, wherein the plurality of agglomerates comprise polyvinylchloridelatex.
 24. The glove of claim 21, wherein the agglomerates comprisepolyvinylchloride latex.
 25. The glove of claim 16, wherein theagglomerates comprise a natural wax, a synthetic wax, or combinationsthereof.
 26. The glove of claim 21, wherein the agglomerates comprise anatural wax, a synthetic wax, or combinations thereof.
 27. The glove ofclaim 22, wherein the agglomerates comprise a natural wax, a syntheticwax, or combinations thereof.
 28. The glove of claim 25, wherein thenatural wax is saponifiable.
 29. The glove of claim 28, wherein thenatural wax comprises montan, carnauba, bees wax, bayberry-myrtle,candelialla, carnaday, castor bean, aspartogras, Japan, oricury,retamo-ceri, mimbi, schlock, spermaceti, sugar-cane, wool lanolin; thesynthetic waxes selected from the group consisting of polyethylene,saponifiable modified polyethylene, polypropylene, saponifiable modifiedpolypropylene, or combinations thereof.
 30. The glove of claim 25,wherein the synthetic wax comprises polyethylene, a modifiedpolyethylene, polypropylene, a modified polypropylene, or a combinationthereof.
 31. The glove of claim 1, wherein the skin contacting polymericcoating is silicone coated.
 32. A method comprising providing a glovethat comprises a cured outer layer; a cured inner layer adherent to thecured outer layer, the cured inner layer comprising an acrylic polymerand a plurality of agglomerates dispersed therein, wherein theagglomerates form a plurality of raised domains.
 33. A glove,comprising: a cured protective latex film; and a cured skin contactingpolymeric coating adherent to the cured protective latex film, the curedskin contacting polymeric coating comprising polyurethane polymer and aplurality of agglomerates dispersed therein.
 34. The glove of claim 33,wherein the plurality of agglomerates form a plurality of raiseddomains.
 35. The glove of claim 33, wherein the plurality ofagglomerates comprise a natural wax, a synthetic wax, or combinationsthereof.
 36. The glove of claim 33, wherein the natural wax issaponifiable.
 37. The glove of claim 33, wherein the natural waxcomprises montan, carnauba, bees wax, bayberry-myrtle, candelialla,carnaday, castor bean, aspartogras, Japan, oricury, retamo-ceri, mimbi,schlock, spermaceti, sugar-cane, wool lanolin; the synthetic waxesselected from the group consisting of polyethylene, saponifiablemodified polyethylene, polypropylene, saponifiable modifiedpolypropylene, or combinations thereof.
 38. The glove of claim 33,wherein the skin contacting polymeric coating is silicone coated.